1. Field of the Invention
The present invention relates to an interposer and a method of manufacturing an interposer.
2. Description of the Related Art
In view of the demands for high integration and miniaturization of semiconductor devices in recent years, efforts are being made to further develop the so-called “semiconductor three-dimensional (3D) packaging technology” which involves three-dimensionally integrating a plurality of LSI (large-scale integration) chips of a system into a single package.
In the semiconductor 3D packaging technology, elements have to be electrically interconnected three-dimensionally via fine conductive wiring patterns. However, it is difficult to form such fine wiring structures using conventional techniques such as wire bonding. Thus, in the semiconductor 3D packaging technology, a relay substrate having a plurality of via electrodes is used. Such a relay substrate is also referred to as an interposer. By using one or more relay substrates, a fine and complex three-dimensional conductive wiring pattern may be formed.
Such a relay substrate or interposer may be formed, for example, by forming a plurality of fine through holes in a glass substrate, and filling the through holes with conductive material thereafter. For example, International Publication No. WO2010/087483 discloses a technique that involves irradiating an excimer laser on a glass substrate to form a through hole.
A member for an interposer may be manufactured, for example, by irradiating an excimer laser on a glass substrate to form a through hole therein (hereinafter referred to as “glass substrate with through holes”).
Typically, a glass substrate used for manufacturing an interposer is extremely thin (e.g. 0.1 mm) so that a through hole may be easily formed in the glass substrate.
When such a thin glass substrate is used to manufacture a “glass substrate with through holes,” the strength of the “glass substrate with through holes” may be reduced due to the presence of through holes. For this reason, cracks and defects may be created in the “glass substrate with through holes” upon transferring the “glass substrate with through holes” for a next process and/or handling the “glass substrate with through holes” in various process steps, for example.